Commercial hot air impingement cooking apparatus

Abstract

Various representative commericial cooking devices are disclosed wherein a recirculating flow of heated air, at a food cooking temperature, is created within a housing in which a horizontally disposed food support and cooking member, such as a perforated metal plate, a solid griddle plate or a metal broiling grate, is positioned. A plenum structure is utilized to convert a portion of the continuously recirculated air into a spaced series of relatively high velocity heated air impingement jets which are caused to laterally diffuse and at least slightly overlap prior to striking at least one side surface of the food support structure. In this manner, each food support structure side surface subjected to such diffused jet impingment is evenly blanketed with heating air to thereby very uniformly transfer heat from the air to the food support structure, and thus to the food supported thereby, at an accelerated rate.

What is claimed is: 
     
       1. Commercial heated air impingement oven apparatus comprising: a housing having a cooking chamber therein;   a relatively large area heat conductive food support plate member horizontally and stationarily supported within said cooking chamber;   heated air recirculating means for creating and maintaining a recirculating flow of heated air, at a food cooking temperature, within said housing;   first multiple jet forming means, spaced downwardly apart from said plate member in a stationary relationship therewith, for converting a first portion of said recirculating flow of heated air into a mutually spaced series of upwardly directed, relatively high velocity heated air impingement jets which laterally diffuse and at least partially overlap prior to striking the lower side surface of said plate member to thereby evenly blanket said lower side surface with heated air in a manner uniformly transferring heat from said first air portion to said plate member at an accelerated rate;   second multiple jet forming means, spaced upwardly apart from said plate member in a stationary relationship therewith, for converting a second portion of said recirculating flow of heated air into a mutually spaced series of downwardly directed, relatively high velocity heated air impingement jets which laterally diffuse and at least partially overlap prior to striking at least a portion of the upper side surface of said plate member to thereby evenly blanket said upper side surface portion with heated air in a manner transferring heat from said second air portion to said upper side surface portion, and/or a food item supported thereon, at an accelerated rate whereby a food item resting upon said heat conductive food support plate member may be evenly cooked at an accelerated rate without moving the food item within said cooking chamber; and     return means for flowing said first and second air portions outwardly from said cooking chamber and returning them to said heated air recirculating means.   
     
     
       2. The oven apparatus of claim 1 wherein: said food support plate member is uniformly perforated and has a total open area greater than the total open area of said first multiple jet forming means, and said return means are disposed such that at least a major portion of the air issuing from said first multiple jet forming means must pass through said food support plate member.   
     
     
       3. The oven apparatus of claim 1 wherein: said food support plate has a rectangular configuration with a width of approximately 56" and a depth of approximately 36" for accommodating multiple standard sized items to be cooked.   
     
     
       4. The oven apparatus of claim 1 wherein: said heated air recirculating means include first fan means for supplying said first air portion to said first forming means, and second fan means for supplying said second air portion to said second jet forming means, and the flow rates of said first and second fan means are independently adjustable, whereby the cooking heat transfer rates to upper and lower side surfaces of a food item supported on said plate member may be selectively and independent varied.   
     
     
       5. The oven apparatus of claim 1 wherein: said first jet forming means include a plurality of elongated lower plenum means, disposed in a parallel relationship, into which said first air portion is flowed, said lower plenum means having upper wall portions with air discharge openings therein through which air is flowed to form said upwardly directed jets.   
     
     
       6. The oven apparatus of claim 5 wherein: said upper wall portions are corrugated and are provided with upwardly projecting ridges within which generally rectangular air discharge openings are formed to produce upwardly directed diverging jets.   
     
     
       7. The oven apparatus of claim 5 wherein: said plurality of lower plenum means are separated by support members which hold said plate member in an upwardly spaced relationship relative to said plurality of lower plenum means.   
     
     
       8. The oven apparatus of claim 1 wherein: said second jet forming means include a plurality of elongated upper plenum means, disposed in a parallel relationship, into which said second air portion is flowed, said upper plenum means having lower wall portions with uniformly spaced air discharge openings therein through which air is flowed to form said downwardly directed jets.   
     
     
       9. The oven apparatus of claim 8 wherein: said lower wall portions are corrugated and provided with downwardly projecting ridges in which generally rectangular air discharge openings are formed.   
     
     
       10. The oven apparatus of claim 9 wherein: said upper plenum means are positioned only over a front portion of said plate member, and said return means are positioned rearwardly of said plate member.   
     
     
       11. The oven apparatus of claim 10 wherein: said return means are operative to draw said first and second air portions rearwardly through said cooking chamber from between said plate member and said upper plenum means.   
     
     
       12. The oven apparatus of claim 11 wherein: said return means include at least one return opening positioned in a rear wall portion of said cooking chamber.   
     
     
       13. The oven apparatus of claim 8 wherein: said plurality of upper plenum means include a first plenum box structure positioned along a front portion of said cooking chamber, and a second plenum box structure positioned rearwardly of said first plenum box structure, said first plenum box structure having a larger internal cross sectional area than that of said second plenum box structure.   
     
     
       14. The oven apparatus of claim 1 wherein: said housing is sized to fit within a rectangular floor footprint area approximately 63" wide by 45" deep.   
     
     
       15. Commercial heated air impingement oven apparatus comprising: a housing having upper and lower cooking chambers therein;   a first relatively large area heat conductive food support plate member horizontally and stationarily supported within said upper cooking chamber;   a second relatively large area heat conductive food support plate member horizontally and stationarily supported within said lower cooking chamber;   first heated air recirculating means for creating and maintaining within said housing a first recirculating flow of heated air at a food cooking temperature which traverses said upper cooking chamber;   second heated air recirculating means for creating and maintaining within said housing a second recirculating flow of heated air at a food cooking temperature which traverses said lower cooking chamber;   first jet forming means for converting a first portion of said first recirculating flow of heated air into upper and lower mutually spaced first series of relatively high velocity heated air impingement jets which emanate from stationary locations spaced upwardly and downwardly apart from said first plate member, and laterally diffuse and at least partially overlap before transversely striking the opposite sides of said first plate member in a manner evenly blanketing the lower side surface of said first plate member, and at least a portion of the upper side surface thereof, with transversely directed heated impingement air to thereby transfer heat from said first portion of said first recirculating flow of heated air to said first plate member at an accelerated rate;   second jet forming means for converting a first portion of said second recirculating flow of heated air into upper and lower mutually spaced second series of relatively high velocity heated air impingement jets which emanate from stationary locations spaced upwardly and downwardly apart from said second plate member, and laterally diffuse and at least partially overlap before transversely striking the opposite sides of said second plate member in a manner evenly blanketing the lower side surface of said second plate member, and at least a portion of the upper side surface thereof, with transversely directed heated impingement air to thereby transfer heat from said first portion of said second recirculating flow of heated air to said second plate member at an accelerated rate whereby food items resting upon said first and second heat conductive food support plate members may be evenly cooked at an accelerated rate without moving the food items within said upper and lower cooking chambers;     first return means for generally horizontally flowing said first portion of said first recirculating flow of heated air outwardly from said upper cooking chamber and returning it to said first heated air recirculating means; and   second return means for generally horizontally flowing said first portion of said second recirculating flow of heated air outwardly from said lower cooking chamber and returning it to said second heated air recirculating means.   
     
     
       16. The oven apparatus of claim 15 wherein: said first and second plate members have rectangular configuration and are approximately 56" by 36".   
     
     
       17. The oven apparatus of claim 15 wherein: said housing is adapted to fit within a rectangular floor footprint area of approximately 63" by 45".   
     
     
       18. The oven apparatus of claim 15 wherein: said first and second heated air recirculating means comprise first and second supply fan means positioned within said housing and respectively communicating with said first and second return means.   
     
     
       19. The oven apparatus of claim 18 wherein: said first and second fan means are independently operable, whereby a selected one or both of said upper and lower cooking chambers may be selectively operated.   
     
     
       20. The oven apparatus of claim 15 wherein: said first and second jet forming means each comprise upper and lower plenum means positioned above and below one of said plate members for receiving heated air and having facing wall portions with air discharge openings formed therein for discharging air in the form of said impingement jets.   
     
     
       21. The oven apparatus of claim 20 wherein: each of said facing wall portions is corrugated to define ridges which project toward one of said plate members, and said air discharge openings are rectangular slots formed in said ridges.   
     
     
       22. The oven apparatus of claim 20 wherein: said first and second return air means are operative to withdraw air from said upper and lower cooking chambers from locations therein positioned above their plate members and below the upper plenum means associated therewith.   
     
     
       23. An oven for rapidly and uniformly cooking food items such as pizzas, bread, pastries and the like, comprising: a housing having a cooking chamber therein;   a relatively thin, sheet-like food support member horizontally disposed in a stationary position within said cooking chamber and having a lower side surface, and an upper side surface upon which food items to be cooked such as pizzas, bread, pastries or the like, may be supported; and   means for creating within said housing a recirculating flow of air, at a food cooking temperature, which traverses said cooking chamber and simultaneously impinges generally transversely upon said upper and lower side surfaces of said food support member, at a relatively high velocity, in a manner evenly blanketing said upper and lower side surfaces and thereby transferring cooking heat to said food support member at an accelerated rate, whereby food items stationarily positioned on the top side of said food support member may be evenly cooked at an accelerated rate.     
     
     
       24. The oven of claim 23 wherein: said food support member is a thin perforated plate formed from a heat conductive material.   
     
     
       25. The oven of claim 24 wherein: said food support member is a thin, uniformly perforated metal plate.   
     
     
       26. The oven of claim 24 wherein: the open area of said thin, uniformly perforated metal plate is relatively large compared to the solid surface area of one of said upper and lower side surfaces.   
     
     
       27. A method of cooking a pizza comprising the steps of: supporting the pizza of the upper side surface of a stationary, horizontally disposed, perforated thin metal plate; and   causing relatively high velocity air, at a cooking temperature, and in the form of a series of mutually spaced series of overlapping jets directed generally transversely to said plate, to impinge upon and evenly blanket the upper side of the pizza and lower side surface of said plate to transfer cooking heat to the pizza, directly and through the metal plate, at an accelerated rate.